Infused beverages like South American mate, tea, and other herbal drinks require the inundation of the flavoring ingredient by hot water. The best water temperatures for brewing beverages are specific and various, depending on the herb. Preparing these beverages away from home has long been a challenge because of the equipment and precise water temperatures required.
Perhaps the most common form of personal, portable brewing system until now has been a kit consisting of brewing cup, herbal leaves, and thermos filled with hot water. However, such a kit can be large and cumbersome, and unsatisfying too. Pouring from thermos to open brewing cup can lead to spills in moving vehicles or active environments. Additionally, once-hot water in even a good thermos can cool to sub-optimal temperature before use.
Numerous concepts have improved portability by combining thermos, brewing cup and drinking straw in a single compact unit (for example, patents AR 001471, AR 010084, AR 011926, and AR 242491), but the hot water with which the user fills these devices may still cool before he is ready to brew.
There are many electric-powered beverage heaters that both preserve water temperature and offer some degree of portability, like U.S. Pat. No. 6,140,614 and AR 040327. However, these are little more than electric kettles or mugs that plug into automobile cigarette lighters. The devices can heat water or a beverage that is already brewed, but they themselves do not specifically support brewing, and may provide no integrated means for drinking any beverage they contain. A brewing vessel, herbal leaves, and in some cases a cup or straw must be carried and used separately for brewing, so users would find these devices as awkward to employ as earlier thermos-based kits. Portability of these devices is further limited by the need for a 12V automobile battery for power.
Patents AR 233572 and AR 221617 are examples of portable, electrically-powered devices that heat water and are specifically designed for preparing mate or other infusions. However, like most electric kettles or mugs, they fail to provide for a self-contained power source, so their use is similarly limited to automobile or home. Further limiting utility of these electric infusion makers, the user must pour the ready beverage into a separate cup to drink, so spills can still occur in settings like crowded stadiums or moving buses.
Finally, there are many forms of electric coffee maker that are, to a degree, portable. U.S. Pat. No. 6,123,010 even describes one powered by self-contained batteries. However, standard drip coffee makers like U.S. Pat. No. 6,123,010 depend on the use of boiling water. They need the bubbles produced by water heated to 100 degrees Celsius to propel the water up the tube from the heating element in the device's base, to the drip hole above the filter that holds the coffee grounds. Unfortunately, boiling water is strictly contraindicated for mate, select green and oolong teas, and various other herbal infusions. The lower oxygen content of boiling water gives it a higher capacity than sub-boiling water to extract key molecules from delicate herbal leaves. As a result, boiling water (or even boiled water allowed to cool) strips mate and similar leaves of their flavor in a single steeping, instead of allowing for the measured release of flavor over a number of steepings, as custom requires. The optimal water temperatures for mate and select Chinese teas range from 70 to 80 degrees Celsius—far cooler than the boiling temperature that standard drip coffee makers universally produce. In addition, U.S. Pat. No. 6,123,010 is clearly too large to be considered personal and portable, and would have to dispense beverages into a separate cup, with the attendant risk of spills. The detachable beverage mug also described in the U.S. Pat. No. 6,123,010 patent document is small and portable, spill-proof and powered by a self-contained battery, but it lacks any provision for brewing and functions no differently than electric mugs already discussed.
By contrast, the present invention permits the heating of water to any target temperature, and the brewing of a beverage in multiple, discrete steepings, in accordance with the South American mate and Chinese Gongfu tea traditions. Within a small and portable, spill-proof unit, the device brews hot beverages at the moment of use for freshest flavor and (in preferred embodiments) perfect temperature with every swallow. The invention enables the user to accomplish high-quality brewing while riding the subway or sunning at the beach far from stove, household outlet or automobile.
The present invention addresses shortcomings in prior art in the following ways:                1) It is a small and portable, integrated and enclosed device for brewing hot beverages like South American mate and tea that heats cold water to target temperature by power of a self-contained battery. Because the device's battery is self-contained, users will be able to brew and drink hot beverages virtually anywhere they go, including on moving vehicles and in crowds, and even when stove, household outlet, and car battery are not accessible. Prior inventions fail to achieve the foregoing specification in one or more of the following ways: a) they are not small enough to carry easily; b) they lack specific provisions for brewing; c) they consist of multiple loose parts carried or used separately; d) they are open to spills; or e) they are not powered by self-contained battery for absolute freedom of movement.        2) It is as described in point 1 above, and employs serial heating, heating only a small amount of water at a time. Earlier electric infusing devices require heating the total volume of water they contain, and then infusing that full volume before the user can start to drink.                    By contrast, the present invention capitalizes on the serial brewing method characteristic of South American mate and Chinese Gongfu tea traditions. With mate and select green and oolong teas, the leaves for infusion are steeped not once, but up to 8 or more times. The small quantity of infusion produced by each steeping is consumed by the user before the leaves are inundated again with hot water for the next steeping. When the flavor is finally deemed exhausted, the used mate or tea leaves are discarded and replaced by fresh leaves for a new round of brewing.            Consonant with these traditions, the present invention heats just 1 ounce of water at a time, and brews just 1 ounce of mate or tea infusion at a time, and can repeat this process 8 or more times to produce a full serving of 8 ounces or more of beverage before being refilled with water and fresh herbal leaves. The advantages derived from this serial heating process are: a) a much shorter time that the user must wait for water to be heated before the first sip; b) more efficient energy use, with resulting benefits in the weight, size and cost of the battery; and c) a more satisfying drinking experience that emulates traditional mate and Gongfu tea practices.            The first advantage of serial water heating (as opposed to the total-capacity heating of prior art) is a dramatically shorter wait-time for the user. Comparable electric infusing devices of prior art would apply heat to all of the water they contained until the total volume reached target temperature and the brewing and drinking could begin. By contrast, the present invention utilizes a heating chamber—separate from the main water storage compartment—in which just 1 ounce of the device's total water capacity can be heated and then distributed to the brewing chamber for infusion. As a result, for two devices of equal wattage, and holding equal 8-ounce total volumes of water for infusion, the present invention will produce infusion for the user's first sip in just ⅛ the waiting time required by a device of prior art (since 1 ounce takes ⅛ the time to heat that 8 ounces take). Then, as the user of the present invention sips the first ounce of infusion, an ounce of water for the next steeping can be heated simultaneously. In this way, he can drink 1 ounce of his hot beverage after another with little or no waiting between steepings, until the entire 8-ounce serving is consumed.            In addition to shortening waiting time, serial heating saves energy. Because the invention heats only as much water as the consumer will use immediately (1 ounce), it does not waste energy maintaining water temperature as total-capacity heating would require. Consequently, the present invention's battery can be small and light enough for containment in a personal, portable brewing system—an objective previous art could never achieve.            Finally, serial heating and brewing preserve certain key qualities of the mate- and Gongfu tea-drinking experiences. Both traditions highly prize the leisurely consumption of the beverages. In both, the infusions are typically consumed in quantities of about 1 ounce at a time, to permit the careful appreciation of flavor.                        3) It is as described in points 1 and 2 above, and has a folding drinking straw. The folding straw makes the invention more compact by folding out of the way when not needed. It is also very convenient to deploy or store with just a single motion, according to the user's changing wishes. Also, because the straw remains attached, it can never be lost.        4) It is as described in points 1-3 above, and has a single-motion 3-way vent cap. The vent tubes from the water tank, heating chamber and brewing cup all terminate at a single vent cap that the user can open and close with a single, simple motion.        5) It is as described in points 1-4 above, and has push-button water valves. The valve controls, operable by one hand, allow the user to move water easily from water tank, to heating chamber, to brewing cup—all from the outside of the device, without open pouring and the risk of spills.        